Turks are furious about the bill passed in the French parliament on Thursday which publicly recognises as genocide the mass killing of Armenians in the Ottoman Empire in 1915.

Appalling atrocities were committed in the declining years of the Ottoman Empire

Demonstrators laid black wreaths outside the French embassy in Ankara on Friday to register their condemnation of the vote, and in Istanbul protesters scuffled with riot police and threw eggs at the French consulate.

Tempers have frayed, and the Turkish ambassador has been recalled from Paris for consultations. The Prime Minister, Bulent Ecevit, has talked of a serious crisis in bilateral relations.

So what next? The government has drawn up a list of possible sanctions, and French companies could find themselves shut out of lucrative tenders in the defence and energy sectors which are worth billions of dollars.

The Ottoman Government regarded its Armenian citizens as "the enemy within"

Consumer and trade groups have called for a voluntary boycott of French products, and Istanbul University has said it is suspending scientific co-operation with French institutions. It could take years to repair the damage.

For the Armenian diaspora, though, it has taken decades for them to get their message onto the international agenda. Now they hope to go further, but Turkey intends to fight them all the way.

'Genocide campaign'

This bitter dispute is rooted in a violent period of world history, as Europe and much of the Middle East was torn apart by World War I.

Armenians celebrate getting their message onto the international agenda.

Everyone involved knows there were appalling atrocities committed in the declining years of the Ottoman Empire.

During the war, the Armenians fought with the Russians, the Turks with the Germans, and the Ottoman Government regarded its Armenian citizens as "the enemy within".

Modern Turkey admits that thousands of Turks and up to 300,000 Armenians were killed in widespread clashes between 1915 and 1917.

But Armenians insist the number was far higher. They believe 1.5 million of their ancestors were killed in an organised campaign of genocide, designed to wipe out an entire race. Many died on a long march into exile in the Syrian desert.

Both sides produce stacks of documents to back up their arguments, and the Turks say the issue should be left to the historians.

Many researchers, however, complain that they have not been given full access to the Ottoman archives to make a proper assessment.

And so the dispute rages on. It's now become a serious political issue between Turkey and France, home of the largest Armenian community in western Europe.

Many French politicians who voted in favour of the bill in the national assembly say they had no intention of condemning modern Turkey, but most Turks believe that is exactly what has happened.